JP5917769B2 - Drug delivery device - Google Patents

Description

  The present invention relates to a drug delivery device, and more particularly to a device capable of delivering a user-set dose of a drug prior to delivery.

Background Many devices for delivering drugs are commercially available and patented. The drug is placed in a container such as a syringe, cartridge, etc., and the drug is pressurized when delivered. A very common design is a generally cylindrical compartment with a stopper at one end of the compartment and a needle, nozzle or other member that can deliver the drug to the patient at the opposite end. It is installed.

  In order to deliver a certain amount of drug, pressure is applied to the stopper, ie, the plunger rod pushes the stopper into the compartment. In the case of a simple handheld syringe, this can be done manually with a finger. Alternatively, it can be performed by a pressure means such as a spring, which is common in automatic or semi-automatic syringes. In this connection, so-called pen-type syringes are becoming very common. In the case of a pen injector, the injection is made by manually pushing the distal end of the device. This type of syringe has provided an advance in terms of delivering different doses with the same device, ie a predetermined dose can be set prior to delivery.

  Many such devices have been developed, such as the device disclosed in EP-A-1601395. The device includes a dose setting drum, which can be rotated relative to the housing and drive sleeve, and when manually operated by the user, drives the plunger rod to deliver a set dose of medication. In order to achieve the function of setting the dose with the dose setting drum and delivering the dose with the drive sleeve, some kind of connection / separation mechanism is required between them. Therefore, in order to realize a desired function, a clutch or a unidirectional connection mechanism has been developed. This solution requires a large number of parts cooperating with each other and a large number of threaded engagement and connection mechanisms, which prevents excessive force manually applied by the user. In order to require careful design. Otherwise, the device will not function properly. It is also questionable whether the solution according to EP-A-1601395 makes it possible to reset the set dose in a simple and efficient manner.

  Another feature of the device of EP-A-1601395 is that it is necessary to prevent setting a dose higher than the remaining amount. That is, when the nut reaches the end of the helical thread of the connection mechanism, the nut stops the rotation of the dose dial sleeve, thereby locking the drive sleeve and setting the rotation of the dose dial sleeve and setting more doses. Both are prevented. This direct action between threads is not so accurate and there is no clear stop between components. Rather, the components may be rotated relative to each other by a substantial rotational distance until the friction increases and it becomes difficult to rotate the components relative to each other. Thus, the user may fall into the illusion of receiving more doses than actually received.

  In addition, components such as the dose setting drum and the drive sleeve and the plunger rod are elongate and arranged inside each other. Some play is required to avoid the risk of clogging between these components. In that case, such play and gaps between the components increase the risk of lack of support and the occurrence of rattling and other noise that can adversely affect potential users.

SUMMARY An object of the present invention is to provide a drug delivery device in which the deficiencies of the state of the art device are repaired.

  In order to overcome one or several of the above problems, a drug delivery device according to independent claim 1 is provided.

  Other aspects, improvements, and modifications are disclosed in the dependent claims, the drawings, and the specification.

  When the term “distal” is used in this application, this means the direction away from the dose delivery site. When the term “distal part / end” is used, this means the part / end of the delivery device or the part / part of the delivery device that is furthest from the dose delivery site when using the drug delivery device. Means the end. Similarly, when the term “proximal” is used, this means the direction towards the dose delivery site. When the term “proximal part / end” is used, this means that the part / end of the delivery device or the part / part of the delivery device that is closest to the dose delivery site when using the drug delivery device. Means the end. Furthermore, the term “longitudinal”, “axis” or “longitudinal” means the direction or axis of the device or its components in the direction of the longest extending part of the device or its components. Similarly, the terms “transverse direction”, “axis” or “transverse direction” refer to the direction or axis of the device or its components in a direction generally perpendicular to the longitudinal direction. Also, unless otherwise stated in the following description describing the mechanical structure of the device and the mechanical interconnection of its components, the device is initially in a non-activated or non-operated state.

  The present invention provides a drug delivery device comprising a housing having a proximal end and a distal end. A hollow piston plunger is disposed in the housing. The piston plunger has a longitudinal axis that generally corresponds to the longitudinal direction of the drug delivery device.

  The apparatus of the present invention comprises a hollow piston plunger disposed within the housing and a telescopic dose drum disposed concentrically between the housing and the piston plunger. The telescoping dose drum is movable in two directions relative to the housing and relative to the piston plunger when setting the dose and delivering the dose.

  A piston plunger drive means is also arranged in the device for driving the hollow piston plunger towards the proximal end. The piston drive means may include a hollow drive drum sleeve movably disposed in the hollow piston plunger. This may also be fixedly connected to the telescopic dose drum. Thus, the hollow drive drum sleeve and the hollow piston plunger can be coupled together. In this regard, it should be understood that the coupling can be a coupling by many designs to provide the desired functionality.

  The apparatus further comprises an elastic spin element having a longitudinal rod movably disposed within the hollow drive drum sleeve, the longitudinal rod and the hollow drive drum sleeve being detachable from each other. The longitudinal rod and the hollow drive drum sleeve can be coupled to each other by axial movement of the elastic spin element towards the proximal end after setting the dose, so that the hollow drive drum The drum sleeve and the hollow piston plunger are also coupled together, so that the hollow piston plunger and the telescoping dose drum are displaced toward the proximal end to deliver the set dose and the set dose After delivery, the longitudinal movement of the elastic spin element towards the distal end decouples the longitudinal rod from the hollow drive drum sleeve. And, thereby, the bond between the hollow drive drum sleeve and the hollow piston plunger also released for a new dose setting.

According to a preferred feature of the present invention, the apparatus further includes a stopper portion, but is rotatable sliding incapable state with respect to the stop portion is a hollow piston plunger retaining portion is connected to the hollow piston plunger, And the stop is connected to the telescopic dose drum with the stop being slidable but not rotatable with respect to the telescopic dose drum. With this solution it is not possible to set a dose higher than the amount remaining in the drug container. In this way, the user is warned that the dose being delivered is less than the predetermined dose. Preferably, also by indicating to the user how much the last dose is, when the medication container is replaced with a new one or when the user obtains another medication delivery device, Allow a dose to be captured to be delivered to the user.

  According to one preferred solution, the stop cooperates with a stop member on the telescopic dose drum to inhibit rotation of the telescopic dose drum when the set dose is equal to the dose remaining in the drug container. As configured. In this regard, the stop is a generally annular portion including at least one protrusion, rib, or ledge on its outer surface, and the telescopic dose drums are slidably disposed with respect to each other at a first distal end. And a second proximal portion, the second proximal portion is a tubular body including at least one longitudinally extending groove on an inner surface thereof, and the stop member is the at least one This is the end face of the groove. This design provides a purely mechanical stop mechanism. Also, radial support for the piston plunger is obtained when using a rotatable annular member. Thereby minimizing play between components and still minimizing friction between these components.

  A dose setting knob may also be arranged, and the dose setting knob is configured to set the dose when being gripped by the user and rotated in the first direction. The dose setting knob is preferably located in the distal region of the device for easy access.

  Further, the dose setting knob is preferably a separate part connected at its distal end to the first part of the dose drum. As an alternative, the dose setting knob may be integrated with the first part. Thereby, the first portion of the telescoping dose drum is configured to rotate in the distal direction in the first direction relative to the housing during dose setting by the dose setting knob.

  As another alternative, the dose setting knob may be a separate part connected at its distal end to the drive drum sleeve. As another alternative, the dose setting knob may be integrated with the drive drum sleeve. Accordingly, the drive drum sleeve is configured to rotate and move in the far direction in the first direction with respect to the housing during the dose setting by the dose setting knob.

  Further, the device may comprise unidirectional means for preventing the piston plunger from moving in the distal direction while setting the dose.

The drug delivery device may be an injection device, preferably a pen injector.
Other aspects, features, and advantages will become apparent from the foregoing summary, as well as from the following description, including the drawings and the claims.

  The following drawings disclose embodiments of the invention for purposes of illustration only. In particular, the disclosure in the drawings is not intended to limit the protection scope of the present invention. The embodiments shown can be varied in many ways within the scope of the claims.

1 shows a perspective view of a drug delivery device according to a preferred embodiment of the present invention shown in an initial state. FIG. FIG. 2 shows a perspective view of a drug delivery device according to the preferred embodiment of FIG. 1 shown in a state when a single dose is set. FIG. 2 shows a perspective view of a drug delivery device according to the preferred embodiment of FIG. 1 shown after a set dose has been delivered. FIG. 2 is a perspective view of a drug delivery device according to the preferred embodiment of FIG. 1 shown with all of the drug delivered. Figure 2 shows an exploded view of a drug delivery device according to the preferred embodiment of Figure 1; FIG. 2 is a partially exploded view of the drug delivery device of FIG. 1. FIG. 2 is another partially exploded view of the drug delivery device of FIG. 1. FIG. 2 shows a cross-sectional view of the drug delivery device of FIG. 1 shown in an initial state. FIG. 9 is a detailed cross-sectional view taken from a region IX shown in FIG. 8. FIG. 9 is a detailed cross-sectional view taken from a region X shown in FIG. 8 . FIG. 9 is a detailed cross-sectional view taken from the region XI shown in FIG. 8 .

DETAILED DESCRIPTION Mechanical Structure of Embodiment FIG. 1 shows a perspective view of a drug delivery device according to a preferred embodiment of the present invention. The drug delivery device includes a housing 10 having a proximal end and a distal end and having a proximal portion or end 11 and a distal portion or end 12. With the drug delivery device assembled, the housing 10 forms part of the outer surface or appearance of the drug delivery device. However, it should be understood that the housing can be designed in many other ways.

  The drug delivery device further includes a drug container holder 80 that houses the drug container. The drug container holder 80 also forms part of the outer surface or appearance of the drug delivery device. The proximal portion of the container holder 80 further comprises a neck 82 at its proximal end for mounting a conventional injection needle (not shown) known per se. However, it should be understood that other types of connecting members such as bayonet lure-lock fittings may be arranged. Further, an injection needle may be incorporated in the main body of the medicine container, and in this case, the neck portion 82 may be omitted.

  A cap (not shown) may be provided to cover the proximal end of the drug delivery device when not in use, and thus the proximal end of the drug container holder 80, in a removable state.

  The drug container holder 80 of the drug delivery device allows the user to see the advance of the drug, i.e. whether the drug delivery device remains in the initial stage where no drug has yet been injected or the drug container A window 81 is included that allows the user to see if is already empty. The user can see through the window 81 at least the drug container housed in the drug container holder 80 (the distal end of the drug container may have reached into the proximal portion of the housing). In a preferred embodiment, two such windows are arranged on both sides of the drug container holder 80.

Further, the distal end 12 of the housing 10, yet another window 13 is provided. This window is provided to show the set dose to the user, as will be described in more detail below. In the distal end 12 of the housing 10, the dose setting knob 41a for dose setting protrudes distally.

  FIG. 1 shows the drug delivery device in the initial state. When the user grabs the dose setting knob 41a and turns it in a first direction, e.g., clockwise, the dose setting knob 41a and other components are used to set a single dose, as will be described in detail below. Move in the distal direction. FIG. 2 shows a perspective view of the drug delivery device in such a state, ie when a single dose is set.

FIG. 3 shows a perspective view of the drug delivery device after a set dose has been delivered. It can be seen that the dose setting knob 41a and the components connected thereto are moved proximally and the dose setting knob 41a is again in its initial position. However, as can be seen in the window 81, the piston plunger 20 of the drug delivery device has been moved in the proximal direction, at which point the stopper 29 in the drug container can be seen through the window 81.

  Next, FIG. 4 shows a perspective view of the drug delivery device with all drugs, ie several individual doses delivered. At this point, the stopper 29 is located at the proximal end of the drug container 85 and a portion of the piston plunger 20 with the threaded surface 21 can be seen through the window 81.

The drug container holder 80 includes mounting means for connecting or mounting the holder to the proximal portion 11 of the housing 10 . In the embodiment shown, the mounting means includes a protrusion 83 (see FIG. 5) that fits into the corresponding recess 14. However, it should be understood that other attachment members for attaching the drug container holder 80 to the housing 10 may be utilized, such as bayonet fittings, threads, and the like.

  An elongated piston plunger 20 (see FIGS. 5-7) is disposed inside the housing 10 and has a longitudinal axis that generally corresponds to the longitudinal direction of the drug delivery device. The piston plunger 20 has a thread 21 (FIG. 6) on at least a part of its outer surface. In the preferred embodiment shown in the drawings, the proximal portion of the piston plunger 20 includes a threaded structure 21. On its outer surface, the piston plunger 20 includes at least one longitudinal groove 25 (FIG. 6) (in the embodiment shown, two such grooves 25 are provided). At the proximal end of the piston plunger 20, a washer or spinner 28 (FIG. 5) adapted to abut against the stopper 29 is disposed. The stopper 29 is intended to be housed inside the medicine container 85 in a movable state.

The piston plunger 20 is fitted into an insert 50 provided with a central passage 51 (FIG. 7). The center of this central passage generally coincides with the longitudinal axis of the drug delivery device. The central passage 51 of the screw insert comprises a thread 52 designed to be complementary to the thread 21 of the piston plunger 20. The outer surface of the insert 50 includes at least one protrusion 53 or the like that fits into a corresponding recess 15 (FIG. 5) on the inner surface of the housing 10. As a result, the insert 50 is locked to the proximal portion 11 of the housing 10 . As shown in FIG. 5, the recess 15 of the housing may be formed as a through hole.

  The insert 50 further includes a central bore 54 distal to the screw insert 50. Since the diameter of the central bore 54 is larger than the diameter of the central passage 51, a stepped configuration is provided. A ratchet 55 extending in the circumferential direction provided with serrated teeth is provided on the inner peripheral surface of the central bore 54.

  The ratchet 55 cooperates with an annular counter rotating block element 60 (FIG. 7). This block element is provided with two arms 62 arranged opposite to each other on the outer peripheral surface 61 and extending substantially in the circumferential direction of the block element 60. Although two such arms 62 are shown in FIGS. 5 and 7, depending on the size of the block member 60, one arm may be sufficient, or three or more arms may be used. It may be provided. The one or more arms 62 are generally flexible in the radial direction. A ledge 63 is disposed on the outwardly facing surface of the arm 62. Each ledge 63 has a complementary shape to the ratchet 55 of the screw insert 50. The counter-rotating block element 60 is further provided with a central passage 65 (FIG. 7) through which the piston plunger 20 extends. The central passage 65 is provided with a projecting portion or rib 66 directed radially inward, and the projecting portion 66 fits into the elongated groove 25 on the outer surface of the piston plunger 20. With this structure, rotation lock of the piston plunger 20 is realized, but the piston plunger 20 can move in the longitudinal direction.

The piston plunger 20 is further provided with a plurality of longitudinal splines or ribs 23 provided on the inner peripheral surface 22 of the hollow piston plunger 20 (FIG. 7). The generally cylindrical drive drum sleeve 30 (FIG. 5) is disposed on the radially inner side of the piston plunger 20. The drive drum sleeve 30 has a distal end wall 31 that intersects the longitudinal axis of the drive drum sleeve 30. The distal end wall 31 has a central opening and the drive drum sleeve is hollow to accommodate the elastic spin element 70 as will be described below. The proximal end of the drive drum sleeve 30 includes one or more, preferably two, proximally extending flexible arms 33. As will be described below, the arm 33 is flexible in the sense that it can deflect in the radial direction when it receives a radial force. The outer surface of each flexible arm 33 is a radially projecting piston plunger engaging surface 34 (FIG. 9 ) for selectively engaging a longitudinal spline 23 on the inner peripheral surface 22 of the piston plunger 20 . including. The shape of the surface 34 may generally correspond to the shape of the ribs 23 arranged in the circumferential direction of the piston plunger 20. The inner surface of each flexible arm 33 includes a radial engagement protrusion 37 (FIG. 9 ) for selectively engaging an elastic spin element 70 located in the hollow drive drum sleeve 30.

  The distal end wall 31 forms a coupling element by two locking arms 35 (FIG. 5) extending in the proximal direction. The locking arm 35 includes a locking structure 36 for locking the drive drum sleeve 30 to the inner surface of the dose drum 40 at each outer surface.

A telescopic dose (setting) drum 40 is disposed outside the piston plunger 20 when viewed in the radial direction (FIGS. 5 and 6). The dose drum 40 is generally cylindrical and is disposed coaxially with the piston plunger 20 and the housing 10. Dose drum 40 includes a first part component 41, and a second part component 42, which are slidably disposed with each other. The first portion 41 is coaxial with the second portion 42 of the dose drum 40 and is located radially outward.

The first portion 41 is Oite on its external face comprises a groove 49 extending in a helical or spiral (Figure 6). The groove 49 extends throughout from the proximal end of the dose drum 40 to the first portion 41. The groove 49 cooperates with at least one protrusion or spirally extending ledge segment 16 (FIG. 5) located on the inner surface of the housing 10 to rotationally connect the dose drum 40 to the housing 10 and thus These mutual rotations are intended to move the part in the longitudinal direction. The distal end region of the first portion 41 of the dose drum 40 is further configured to lock the drive drum sleeve 30 when the drive drum sleeve 30 is moved into the piston plunger 20 during assembly of the drug delivery device. A locking structure that engages 36 is provided.

  A dose setting knob 41a is disposed at the distal end of the first portion 41 (FIG. 6). The dose setting knob 41a includes a generally cylindrical portion oriented in the proximal direction having a somewhat larger diameter than the outer surface of the first portion 41 of the dose drum 40. The outermost diameter of the dose setting knob 41 a is preferably in the same plane as the outer diameter of the housing 10. The first portion 41 of the telescoping dose drum 40 is thus configured to rotate in the distal direction in the first direction relative to the housing 10 during dose setting by the dose setting knob 41a.

  The inner peripheral surface 44 of the second portion 42 of the telescopic dose drum 40 is connected to the threaded outer peripheral surface 21 of the piston plunger 20 with a screw thread. Specifically, the proximal end of the second portion 42 includes a threaded structure 45 (FIG. 6). The pitch of the thread connection between the first portion 41 of the telescopic dose drum 40 and the inner peripheral surface of the housing 10 is such that the inner peripheral surface 44 of the second portion 42 of the telescopic dose drum 40 and the piston plunger 20 The pitch of the thread connection with the threaded outer peripheral surface 21 is different.

In accordance with the present invention, the device further includes a stop 26, the stop being connected to the hollow piston plunger 20 with the stop member being rotatable but non-slidable relative to the hollow piston plunger 20, And the stop is connected to the telescopic dose drum in a state where the stop member is slidable but not rotatable with respect to the telescopic dose drum. The stop portion 26 is linked to a stop member 97 on the telescopic dose drum 40 when the set dose is equal to the dose remaining in the medicine container so that the rotation of the telescopic dose drum 40 is prohibited. Configured. The stop 26 is a generally annular portion that includes at least one protrusion, rib, or ledge 94 on the outer surface (FIG. 6). Further, the second proximal portion 42, which is a cylindrical body, includes at least one longitudinally extending groove 96 on its inner surface, and the stop member 97 is at the end face of the at least one groove. is there. The stop is arranged to fit into a circumferential groove 27 on the piston plunger, which is arranged in the distal end region of the thread 21 on the outer surface of the piston plunger 20. In order to fit the annular body into the groove of the piston plunger, the stopper is provided with a slit 92 and is made of an elastic material, so that the gap of the slit 92 is widened so that the stopper 26 is pushed onto the piston plunger. be able to. The stop 26 is rotatable with respect to the piston plunger when in place, but is locked in the longitudinal direction. The rib 94 of the stop 26 is intended to be fitted into a longitudinally extending groove 96 (FIG. 6) disposed on the inner peripheral surface 44 of the second portion 42. Therefore, the stopper 26 is locked so as not to rotate with respect to the second portion 42, but can slide in the longitudinal direction with respect to the second portion 42.

  The elastic spin element 70 includes a longitudinal rod 71 and a distal push button 72. The push button is intended to function as a contact surface with which the user's finger contacts during drug delivery, as described below. As described above, the longitudinal rod 71 of the elastic spin element 70 is housed in the hollow drive drum sleeve 30. The longitudinal rod 71 includes an engagement structure at its proximal end that includes a circumferential groove 73 (FIG. 9). Adjacent to this groove is a protrusion 74 in the proximal direction and an inclined surface 77 in the distal direction. The size of the groove 73 and its position on the longitudinal rod 71 is such that the radially inwardly projecting portion 37 on the flexible arm 33 of the drive drum sleeve 30 is received in the groove 73 first. Determined. In such an initial stage, the flexible arm 33 is not deflected radially outward, but is not in tension.

The axial length of the elastic spin element 70 when compared to the drive drum sleeve 30 is such that the proximal surface of the push button 72 is in the initial state of drug delivery, i.e., the engagement protrusion 37 is received in the groove 73. , The gap 76 is set apart from the distal surface of the distal end wall 31 of the drive drum sleeve 30 (see FIG. 10). This gap 76 is maintained when the user sets the dose, and the first portion 41 of the dose drum 40, the drive drum sleeve 30, and the elastic spin element 70 move in the distal direction. However, as soon as the push button 72 is pushed in the proximal direction, the push button 72 first fills the gap 76 and moves the longitudinal rod 71 in the proximal direction relative to the drive drum sleeve 30. By such relative displacement, the inclined surface 77 contacts the engaging protrusion 37 on the flexible arm 33 and moves while being pressed against the protrusion, thereby deflecting the arm 33 outward. Engage with the longitudinal splines of the inner surface 22 of the piston plunger 20.

Description of Function and Operation of this Embodiment Setting Operation for Dose to be Delivered FIG. 8 is a cross-sectional view of the drug delivery device in the initial state.

In order to deliver a single dose, the device must be operated to set a single dose. To set the dose to be delivered, the user grasps the dose setting knob 41a located on the housing 10 and the distal portion and turns them relatively. In this case, the dose setting knob 41a is turned clockwise, for example. By turning the dose setting knob 41a, the first portion 41 of the dose drum 40 rotates. Since the spiral groove 49 of the dose drum 40 and the spiral ledge segment of the housing 10 are connected, this rotation causes the first portion 41 of the dose drum 40 to move distally relative to the housing 10. Inside the dose setting drum 40, the drive drum sleeve 30 also rotates. This is because the distal end wall 31 of the drive drum sleeve 30 is also rotationally locked with the dose drum 40. In this way, the drive drum sleeve 30 is connected to the capacity drum 40 so as to be rotatable integrally with the dose drum 40.

The longitudinal ribs 48 of the inner surface 47 of the first part 41 of the dose drum 40 are in contact with the longitudinal grooves 46 of the outer surface of the second part 42 of the dose drum 40. Thus, the first part can slide relative to the second part. In addition, the second portion 42 is also rotated and the second portion 42 moves in the distal direction as the thread 45 engages the threaded surface of the piston plunger 20. However, the speed is lower than that of the first portion 41 due to the difference in pitch. The rotation of the second portion 42 also creates a constant rotational force on the piston plunger 20, thereby rotating the counter rotating block element 60. The reason why this rotation occurs is that the protrusion 66 of the reverse rotation block element 60 is fitted in the groove 25 in the longitudinal direction of the piston plunger 24, so that the rotation lock is made between the block element 60 and the piston plunger 20. It is. However, the arm 62 of the counter-rotating block element 60 is oriented and the arm 62 and the ratchet 55 of the screw insert 50 cooperate so that any rotation of the counter-rotating block element 60 is prevented. In this way, the rotation of the piston plunger 20 is prevented. During rotation, it is preferred that a mark (not shown) on the dose drum 40 is shown through the window or opening 13 at the distal end 12 of the housing 10. Therefore, the patient rotates the dose setting knob 41a until a predetermined dose is displayed.

  If the user mistakenly sets too much dose, the user turns both the dose drum 40 and the drive drum sleeve 30 in the reverse direction by turning the dose setting knob 41a in the reverse direction until the correct dose is reached.

  FIG. 10 shows a cross-sectional view of the drug delivery device in a state when a dose is set. In particular, it can be seen that the gap 76 still exists.

Pre-Dose Drug Delivery Operation To deliver a single dose of drug, the user places the proximal end of the device at the dose delivery site, particularly at the injection site when the drug delivery member is an injection needle. Press. The next step is to push the distal push button 72 at the distal end of the device. Then, the gap 76 is closed by the force applied by the user, and the distal push button 72 contacts the distal end wall 31 of the drive drum sleeve 30.

The force applied to the distal push button 72 first causes the drive drum sleeve 30 to engage the inner surface of the piston plunger 20. This is as described above. Second, when the gap 76 is filled, the force applied to the distal push button 72 causes the dose setting knob 41a to move proximally. This proximal force is transmitted to the dose drum 40, and the threaded connection with the housing 10 causes the dose setting drum 40 to rotate counterclockwise and move in the proximal direction. Since the dose drum 40 and the drive drum sleeve 30 are rotationally locked, the drive drum sleeve 30 also rotates. Since the arm 33 of the drive drum sleeve 30 bends in the radial direction, the radially outer surface 34 of the drive drum sleeve 30 is firmly engaged with the spline 23 of the piston plunger 20.

  Thus, when the dose drum 40 and the drive drum sleeve 30 rotate, the latter also rotates the piston plunger 20. This counterclockwise rotation is made possible by the counter-rotating block element 60 thanks to the design of its arm 62 that contacts the ratchet 55 of the screw insert 50. Thus, the piston plunger 20 rotates with the counter-rotating block element 60 and provides audible and tactile identifiable information as the arm 62 of the counter-rotating block element 60 slides on the ratchet 55 of the screw insert 50. Furthermore, since the piston plunger 20 is threadedly connected to the screw insert 50, it rotates to move proximally, so that movement of the piston plunger 20 moves the stopper 29 proximally, A dose of drug is released through the drug delivery member. This dose delivery is complete when the dose drum 40 has moved back to its initial position. The initial position can be limited by some sort of blocking member (not shown) that prevents the dose drum from further moving or rotating.

  The device may then be removed from the drug delivery site and the drug delivery member is discarded. If the drug container 85 still contains a sufficient dose for delivery, the above steps may be repeated from the “Dose setting operation for delivery” step.

  However, if the dose contained in the drug container is less than the predetermined dose, the present invention prevents the dose from being set higher than the remaining dose. When the dose setting knob 41a is rotated as described above, the second portion 42 of the dose setting sleeve also rotates in relation to the piston plunger 20, and the second portion 42 and the piston plunger 20 are threadedly connected. As a result, the second portion 42 moves in the distal direction. The rib 94 of the stop 26 slides in the groove 96 of the second portion 42 during rotation, but when the maximum dose is set, the projection 94 is the end face of the groove 96, which is the stop member 97. In contact (FIG. 11), thereby preventing further doses from being set. In this manner, the stopper 26 prevents the dose setting knob 41a from being further rotated, so that setting of a dose higher than the remaining dose is prevented.

  Preferably, the device is provided with some indicia or other information means indicating an amount less than the last, single dose so that the user can then ingest the amount to capture the missing amount. To. In this way, by using all the medicines in the medicine container, it is possible to prevent the medicines that are wasted from remaining because the remaining dosage is smaller than the predetermined dosage.

  While the invention has been illustrated and described in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be appreciated that one skilled in the art may make changes or modifications within the scope of the following claims. In particular, the invention encompasses still other embodiments with any combination of features from the different embodiments described above and below.

  Further, the word “comprising / including” in the claims does not exclude other elements or steps. The indefinite article “a” or “an” (one) does not exclude a plurality. One part may fulfill the functions of several features recited in the claims. The terms “essentially”, “about”, “approximately”, etc., associated with an attribute or value specifically define the attribute itself or the value itself. Any reference signs in the claims should not be construed as limiting the scope.

Claims (12)

A drug delivery device comprising:
A housing (10) having a proximal end (11) and a distal end (12);
A hollow piston plunger (20) disposed in the housing (10);
A telescoping dose drum (40) disposed concentrically between the housing (10) and the piston plunger (20), wherein the telescoping dose drum (40) is adapted to set and dose the dose; When delivering, is movable in two directions relative to the housing and relative to the piston plunger, the drug delivery device further comprising:
Piston plunger driving means for driving the hollow piston plunger toward the proximal end, the piston plunger driving means comprising:
A hollow drive drum sleeve (30) movably disposed in the hollow piston plunger (20) and fixedly connected to the telescopic dose drum (40); 30) and the hollow piston plunger (20) are removably connectable to each other, the drug delivery device further comprising:
An elastic spin element (70) having a longitudinal rod (71) movably disposed in the hollow drive drum sleeve (30), the longitudinal rod (71) and the hollow drive drum The sleeves (30) are removably connectable to each other, thereby
After setting the dose, the longitudinal rod (71) and the hollow drive drum sleeve (30) are coupled to each other by axial movement of the elastic spin element (70) towards the proximal end, thereby The hollow drive drum sleeve (30) and the hollow piston plunger (20) are also coupled together, so that the hollow piston plunger (20) and the telescopic dose drum (40) are set as described above. Displaced toward the proximal end to deliver a dose;
After delivery of the set dose, the longitudinal movement of the elastic spin element (70) towards the distal end decouples the longitudinal rod (71) from the hollow drive drum sleeve (30) Thus, the coupling between the hollow drive drum sleeve (30) and the hollow piston plunger (20) is also released for setting a new dose,
The drug delivery device further comprises a stop (26) , wherein the stop (26) is rotatable but not slidable relative to the hollow piston plunger (20). Is connected to the hollow piston plunger (20) and the stop (26) is slidable but not rotatable with respect to the telescopic dose drum, the stop (26) A drug delivery device connected to a telescopic dose drum.   The stop (26) cooperates with the stop member (97) on the telescopic dose drum (40) when the set dose is equal to the dose remaining in the drug container, and the telescopic dose drum ( 40. The drug delivery device of claim 1 configured to inhibit rotation of 40).   3. A drug delivery device according to claim 1 or 2, wherein the stop (26) is a generally annular portion comprising at least one protrusion, rib or ledge (94) on its outer surface.   The telescoping dose drum (40) comprises a first distal portion (41) and a second proximal portion (42) slidably disposed relative to each other. The drug delivery device according to any one of the above. The telescopic dose drum (40) includes a first distal portion (41) and a second proximal portion (42) slidably disposed relative to each other;
The second proximal portion (42) is a tubular body including at least one longitudinally extending groove (96) on an inner surface thereof, and the stop member (97) is an end face of the at least one groove. The drug delivery device according to claim 2 , wherein   The first distal portion (41) includes a dose setting knob (41a) at its distal end, when the dose setting knob (41a) is gripped by the user and rotated in a first direction. 6. A drug delivery device according to any one of claims 4 to 5 configured to set a dose.   The dose setting knob (41a) is a separate part connected at its distal end to the first portion (41) of the dose drum (40), or the dose setting knob (41a) The first part (41) so that the first part (41) of the telescoping dose drum (40) is being dosed by the dose setting knob (41a), 7. The drug delivery device according to claim 6, configured to rotate in a distal direction in a first direction relative to the housing (10).   The drug delivery device according to any one of the preceding claims, further comprising a drug container holder (80) adapted to receive a drug container (82).   The drug delivery device according to any one of claims 1 to 8, wherein a part of the outer peripheral surface (21) of the piston plunger (20) is threaded.   10. A drug delivery device according to any one of the preceding claims, further comprising unidirectional means for preventing the piston plunger (20) from moving in the distal direction while setting a dose. The drug delivery device Ru der injection device, a drug delivery device according to any one of claims 1 to 10. The drug delivery device according to claim 11, wherein the injection device is a pen-type syringe.

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